Abstract:
High-precision aerodynamic data is usually expressed in table form. To fitting tabular aerodynamic data in trajectory optimization of glide vehicles, a two-dimensional smoothing and shape-preserving fitting method was proposed. Firstly, one-dimensional smoothing and shape-preserving fitting was performed on the tabular aerodynamic data. And then the fitting dimension was expanded by the tensor product method. Finally, the proposed fitting method was validated by fitting typical tabular aerodynamic data. The results show that, under the given fitting accuracy constraints, the method can fit second-order continuous surfaces with the monotonicity maintained in the tabular data. Establishing a trajectory optimization model of glide vehicles based on the tabular aerodynamic data fitted by this method, and optimizing the trajectory using adaptive Legendre-Gauss-Radau collocation method, a trajectory simulation was carried out taking the pitch angle of the optimized trajectory as open-loop control commands. The trajectory optimization results correspond exactly with the simulation results.